body{
    min-height:1000px;
}
.header{
    height:40px;
    text-align: center;
    line-height: 40px;
    font-weight: bold;
}

.ad{
    height:100px;
    text-align:center;
    border-top:1px solid #9e9e9e;
    border-bottom:1px solid #9e9e9e;
}
